Getting Enough Sleep Can Help Reduce Weight Gain

Sleep deprivation alters hormones and increases appetite, according to the results of a brief randomized study.

The study was published in the Dec. 7 issue of the Annals of Internal Medicine. The editorialists suggest that getting enough sleep may help reduce weight gain.

"Total sleep deprivation in rodents and in humans has been associated with hyperphagia," write Karine Spiegel, PhD, from the University of Chicago in Illinois, and colleagues. "Over the past 40 years, self-reported sleep duration in the United States has decreased by almost two hours."

In this two-period, two-condition crossover clinical study, 12 healthy men were randomized to two days of sleep restriction (four hours per night) and two days of sleep extension under controlled conditions of energy intake and physical activity. Mean age was 22 ± 2 years, and mean body mass index (BMI) was 23.6 ± 2.0 kg/m2. Outcomes were daytime profiles of plasma leptin and ghrelin levels and subjective ratings of hunger and appetite.

"Short sleep duration in young, healthy men is associated with decreased leptin levels, increased ghrelin levels, and increased hunger and appetite," the authors write. "Additional studies should examine the possible role of chronic sleep curtailment as a previously unrecognized risk factor for obesity."

In an accompanying editorial, Jeffrey S. Flier, MD, and Joel K. Elmquist, DVM, PhD, from Beth Israel Deaconess Medical Center in Boston, Massachusetts, wonder if controlled studies should be designed to measure the effect of sleep-promoting interventions on appetite and body weight. However, they note that this study does not prove a cause-effect relationship between the hormone levels and hunger and dietary intake. Other factors, such as cortisol or orexin, may affect sleep and body weight regulation.

"If the findings prove to be reproducible and generalizable, and the hormonal changes of leptin and ghrelin due to sleep curtailment cause changes in food intake over time, we might add sleep duration to the environmental factors that are prevalent in our society and that contribute to weight gain and obesity," the authors write. "Although recommendations to get both a better night’s sleep and more exercise might superficially seem to be at odds with each other from the perspective of energy expenditure and energy balance, these simple goals may well become a part of our future approach to combating obesity." Ghrelin is an appetite stimulant while leptin is an anorexic hormone associated with regulation of appetite and hunger in humans. In young healthy men, short sleep duration is associated with decreased leptin, increased ghrelin, and increased hunger and appetite. Ann Intern Med. 2004;141:846-850, 885-886